1. Field of the Invention
The present invention relates to a solar cell module including multiple solar cells electrically connected with one another by wiring.
2. Description of Related Art
A conventional solar cell module has a configuration in which multiple solar cells are sealed between a front surface protection member and a back surface protection member by a sealant. The multiple solar cells are electrically connected with one another by wiring.
Heretofore, it is known to use conductive resin adhesive when wiring materials are connected to solar cells. With this method, a bonding temperature at which the wiring materials are bonded to the solar cells can be lowered when compared to the use of solder. Thereby, thermal effect on the solar cells can be reduced. This method is disclosed in, for example, Japanese Patent Laid-open Publication No. 2005-101519.
In addition, it has been known that a coloring function from curing is imported to the resin adhesive to check the curing of the adhesive, as disclosed in, for example, Japanese Patent Laid-open Publication No. Hei. 4-145180.
Conventional conductive resin adhesives having a function to be colored include a paste-like one and a tape-like one in a state where it is not cured.
In the case of the paste-like resin adhesive, the degree of spread of the paste at the time of bonding changes depending on a viscosity of the paste, displacement of the paste at the time of application, and variations in the application amount. On the other hand, in the case of the tape-like conductive resin adhesive, the degree of spread of the tape at the time of bonding changes depends on variations in position where the tape is placed and hardness of the tape.
Curing of the conductive resin adhesive includes a thermocompression bonding process in which pressure is applied to the conductive resin adhesive while heat is applied thereto at the same time. The degree of spread of the conductive resin adhesive also changes depending on variations in heat and pressure applied to the conductive resin adhesive at this time.
In the above-described bonding methods, the colored conductive resin adhesive can protrude from a space between a connection electrode and a wiring material to a light-receiving surface of a solar cell, due to a state of the conductive resin adhesive and variations in bonding method. There arises a problem that an output of a solar call module decreases because a power generation effective area is shielded when the colored conductive resin adhesive protrudes to the light-receiving surface as described above.
In addition, when the conductive resin adhesive is designed to prevent protrusion from a tab to prevent the above-described problem, it becomes difficult to check the coloring of the conductive resin adhesive by curing.
The above-described problem is commonly caused when a connection electrode of a solar cell and the solar cell are bonded to each other by a conductive resin adhesive and also when a connection electrode of a solar cell and a wiring material that takes out electricity are bonded to each other by a conductive resin adhesive.